Magnetron



April 30, 1940. H. E. HOLLMANN MAGNETRON Filed Jan. 14, 1939 INVENTOR. HANS ERIC/1 HOLLMANN BY %Z///%M- ATTORNEY.

Patented A r.3o,194o a I 2 177.

iMAGNETRON flans-Erichiflollmann, Berlin, 'Germany,asslgnor toTclefunkcn Gesellschaftiiir Drahtlose Tele- ,graphie n1. ,;b. "11,, Berlin, Germany, alcorpora- ,tion- -ofGermany v Application January :14, 1939, .Serial No; 250;877 In Germany January 26, 1-938 3 Claims. ,.-(Cl. 2 50- -27..5-)- "My'invention relatesto electron discharge deof novel-construction and havingimproved "charvices of the so-called magnetron type in which "acteristics, f l a the electrode system of the device is subjected fAccording' 't'oythe invention, simultaneous sub to a magnetic field during the operation of the division or splitting 'in 'directions parallel to the *5 device. I axis and at right angles thereto is effected by #5 Va,rio us "magnetron tubes have of late been dividing the "anode cylinder into two 'or more evolved and disclosed which one or two helical segments by a helical split,'-'the'-ensuing cathodes are'idisposed outside the anode cylinder divisions or segments in the usual manner being inorder "to protectt-he cathodes irom the extra connected'with one another and with'an os'cill0 heating caused .by "electrons returning "thereto; latory circuit. By'sucha-step the electronsalong 10 lnzoneform of 'suchtubeatheconventional form v their spiral paths will repeatedly encounter split oi magnetron *hasibeen preserved .so far as the fields'in thepresence"of asubstantiallyperpenconstruction and arrangement of the anode is dicular 'fiel'dand of the same rhythm,.'-provide'd concerned; that is .to :say, the anode cylinder that thejpitch of the, helical splits is adapted "to maybe 'close'dupon itself or else be split into the operating-conditions,in 'other'words, to the 15 two, three or more segments which, individually magneticand the, electrical field'intensity. or combined into groups, are associated with a A practical exemplified embodiment of a tube suitable oscillatory circuit, for examplaaLecheras here disclosed is illustrated in Figure 2 in wire system. Another form of tube having exschematic form, the tube being provided with ternal cathodes has a cylindrical anode (or anode two helical anode segments S1 and S2. The 20 cylinder) subdivided not into segments parallel cathode K is mounted at theleft-hand end of to the axis, but by sections at right angles to the anode cylinden, This cathode is rearwardly the axis to result in two or'more rings also united shielded by means of a. flat disc shield B. The into groups. Inasmuch as in these two types of open opposite end of the anode cylinder isclosed tube, the electrons travel along spiral paths from by the disc electrode F, which, if desired, may be 25 the cathode into the interior of the anode cylimpressed with a constant, positive auxilary poinder, it is possible in one case'by slit-fields partential, and which is adapted to adjust the axial allel to the axis as well as in the other case by component of the motion of the electrons, that means of concentric fields to obtain deliveryof is, in the presence of a given magnetic field inenergy at the rhythm or rate of the rotation fretensity, theipitch of .the helical movement. The 30 quency or multiples thereof. anode cylinder, in a way as hereinbefore ex- Fundamentally speaking, it would be self -sug-. plained, is divided by means of two helical splits gesting to combine these two actions in a tube extending in a' sense'contrary to the rotational schematically illustrated inFigure 1 by subdividmotion of the electrons, into two segments S1 ing the anode cylinder both into segments as well and S2 both of which are connected with a suit .35

as into rings so that thereresults a magnetron able resonance circuit, say, an inductance clip tube comprising a great number of segments as or loop L. An electromagnetic coil 'M produces indicated at S1, S1 S S2", etc. How a magnetic field within the space surrounded by ever, it will be readily'understood that the atsaid anode segments and parallel to the longi- 40 tempt to excite all of these different segments in tudinal axis of said segments. Inasmuch as the I 40 phase or in phase opposition and toconnect them time O rotationbr circulation of elelltlons ntogether in a suitable Way so as to resultin two d a hOmOgeneOllS m g fi as Well kn wn groups excited in phase must encounter serio s i always Same, it follows that the helical difiiculties, for the reason that the exciting fresplit field will always i traversed by electrons quencies to be considered for both modes of subat the same rhythm; m other words the division can be madeequal only with great diffi ments at all points are excited at the samefre- V It will of course be'understood that culties, and also on the ground that the complrquency. Gated Connection of such a greatnumber of the helical splitting could be effected by three,

. four, or more segments rather than-in two; and I mentary segments where ultra'hlgh qk e just as in the conventional magnetron tube, the 50 are concerned could never be free o dlsturb' connection thereof may be in pairsor in groups ing Secondary actions primarily because of the with segments placed parallel to the axis. Inv inductances of criss-crossing connecting wires. Order t t t m ti of t compara',

The Object of my invention is to prov d a ,tively long helical segments may be prevented, it electron discharge device of the magnetron type is preferable to connectthe same at a number 55 of points by bridging clips. On the contrary, however, the segments could be used to act also as an oscillatable resonance system though in such case care must be taken so that standing waves will be set up along the segments. However, all of these steps are Well known with the conventional magnetron tube, and they may similarly be adopted in connection with the tube here disclosed Without the necessity of more detailed explanation. 3 i I It goes Without saying that, as to the rest,.a such ways and means as are conductive to improved conditions of excitation in connection with other types of tubes could be applied alsoto the tube here disclosed having helical splits. More particularly, the performance and efiiciency of the tube is increasable by providing two cathodes,

one mounted at each end of the anode cylinder, without the basic idea of the invention, namely,

to provide a helical split of the anode cylinder, experiencing any basic alteration. Moreover, as disclosed in connection with standard external cathode tubes, it is possible to mount in the axis of the discharge system a non-emissive cathode, say, in the form of a rod connected with the cathode proper, to the end of thereby insuring more symmetric voltage conditions.

While I have indicated the preferred embodiments of my invention of which I am now aware and have also indicated only one specific application for which my invention may be employed, it will be apparent that my invention is by no means limited to the exact forms illustrated or the use indicated, but that many variations may be made in the particular structure used and the purpose for which it is employed without departing from the scope of my invention as set forth in the appended claims.

What I claim as new is: v

1. An electron discharge device having an envelope containing a cathode and an anode comprising a. pair of segments provided with helical gaps between said segments, said anode segments being displaced longitudinally of said cathode,

I and means for producing a magnetic field within the space surrounded by said anode segments and parallel to the longitudinal axis of said anode.

2. An'electrondischarge device having an envelope containing a pair of anode segments having helical gaps therebetween, a cathode positioned at one end of said anode segments, an

) electrode positioned at the other end of said anode segments and adapted to have a positive potential applied thereto and means for producing a magnetic field within the space surrounded by said anode segments and parallel to the longitudinal axis of said segments.

3. An electron discharge device having an envelope containing a pair of anode segments having helical gaps therebetween, a cathode positioned at one end of said anode segments, an electrode positioned at the other end of said anode segments and adapted to have a positive potential applied thereto and means for producing a magnetic field within the space surrounded by said anode segments and parallel to the longitudinal axis of said segments, and a shielding device positioned on the other side of said cathode from said anode segments.

HANS ERICH HOLLMANN. 

